1. Field of the Invention
The present invention relates to a jointing tape for bonding wall slabs together, and in particular to a jointing tape having a shielding member which is attached to a joint between two wall slabs so as to cover a space or groove formed in the joint.
2. Description of the Related Art
Conventionally, a wall slab formed into a predetermined dimension, such as a plaster board and an aerated light-weight concrete slab, has been frequently used as an exterior wall or interior wall of buildings. When assembling or joining the wall slabs together, a joint between the wall slabs should be flattened and prevented from being cracked after execution of work.
As shown in FIG. 1 which illustrates a conventional construction method for assembling the wall slabs, the wall slabs A, B are joined together side by side so that taper portions C, D thereof form a V-shaped space or groove F in a joint E therebetween. The space F is then filled with putty G by using a spatula H. In this method, even if the wall slabs A, B are joined together with a slight difference in level, the difference in level is inconspicuously covered or absorbed by the putty G. However, a bonding strength between the wall slabs A, B is relatively low, so a displacement between the wall slabs A, B which causes a crack in the putty G filled in the space F may be easily occurred.
In order to improve the bonding strength between the wall slabs A, B, as shown in FIG. 2 it has been conventionally proposed to use an elongated thin net-like jointing tape J. The jointing tape J is bonded onto the wall slabs A, B by means of an adhesive K so as to cross over the space F, and the putty G is then applied onto an outer surface of the jointing tape J by the spatula H. The space F is filled with the putty G which passes through a large number of meshes or holes of the net-like jointing tape J, and the entire outer surface of the jointing tape J is covered thin with the putty G. Both sides of the jointing tape J is strongly stuck onto wall surfaces of the wall slabs A, B by the putty G which passes through the meshes, and therefore the wall slabs A, B are strongly joined together by the tape J. Thus, the net-like jointing tape J effectively prevents an occurrence of displacement between the wall slabs A and B after execution of work.
However, it is undesirable to fill the space F with the putty G when using the net-like jointing tape J. The space F consumes a large amount of the putty G. The next works such as papering or painting the wall are much delayed because the putty G filled in the space F does not dries up soon. Since the putty G filled in the space F shrinks due to drying, it is difficult to flatten the surface of the putty G by one-time work. Further, it is a troublesome task to stick the jointing tape J onto the wall slabs A, B with the adhesive K.
In FIG. 3, there is shown a jointing tape J to which the adhesive K has been previously applied. In this jointing tape J, the problem is that the adhesive K is applied onto both surfaces of the jointing tape J. The adhesive K applied onto the outer surface of the jointing tape J hinders a smooth motion of the spatula by contacting with the spatula. Further, in order to keep the jointing tape J in a state of being wound into a roll as a bandage, a peeling sheet L put on the outer surface of the jointing tape J is required. Furthermore, the jointing tape J shown in FIG. 3 is also formed into a net, so the putty G enters the space F through a number of meshes of the tape J when applying the putty G onto the outer surface of the jointing tape J.
As shown in FIG. 4, there has been proposed another jointing tape J which has a shielding member M for preventing the putty G from entering the space F. The shielding member M is made of elongated thin stainless steel, and is previously stuck onto an inner surface of the jointing tape J by adhesive N. A width of the shielding member M is longer than that of the space F but shorter than that of the jointing tape J. The jointing tape J is stuck onto the wall surfaces of the wall slabs A, B where adhesive P is previously applied, and the putty G is then applied onto the outer surface of the jointing tape J by means of the spatula. Incidentally, in the case of using the wall slabs A, B as an exterior wall, as shown in FIG. 4, a backup material R and a waterproof sealant S may be filled or interposed between the wall slabs A, B.
The jointing tape J with the shielding member M shown in FIG. 4 prevents the putty G from entering the space F. However, the jointing tape J has the following problems. First, the work for applying the adhesive P onto the wall slabs A, B is required, so construction is troublesome. Second, since the shielding member M is not transparent, it is difficult to align the center of the shielding member M with the center of the space F when sticking the jointing tape J onto the wall slabs A, B. Third, a surface of the shielding member M made of stainless steel is smooth, so the bonding performance between the shielding member M and the putty G is worse. As a result, there may be sometimes the case where the center portion of the jointing tape J floats up.